The invention relates to a rear projection system and more particularly to a large screen television system utilizing a standard television set.
Television has become a basic part of our society and finds use not only in the home but in commercial establishments as well. For home use, the size of the television screen is generally adequate for a family to view the set in a normal sized room. However, in many commercial establishments, the television set is provided for viewing by a large number of patrons. For example, in restaurants, lounges, clubs, etc., the television set may be provided for viewing by the patrons during their visiting the commercial establishment. Additionally, in hospitals, nursing homes, and even industrial locations, a television set is frequently provided for the use of a large number of people, many of whom must view the set from various side directions and distances, and thereby the viewing area is very large.
In addition to commercial use of standard television programs, closed circuit television has become a standard instrument for many purposes. For example, in hospitals, an operation may be monitored by a large audience through the use of closed circuit television, whereby the operation is viewed on the screen of a television set. Similarly, all educational institutions, sports facilities, and security maintenance utilize closed circuit television sets.
One of the difficulties with public and large scale viewing of television screen pictures is the limited size available for the television screen. Normally, a television screen size is approximately 17" to 24", measured diagonally. While these are normally sufficient for home use, it becomes difficult in commercial or industrial establishments for people spread over a wide viewing area to clearly see the program on the television screen. In order to make the television screen bigger, a larger picture tube would be needed which would then add to the bulk and weight of the television set, as well as to the expense involved in manufacturing such a large picture tube.
As a result, when a television set must be viewed or monitored by many people, alternative solutions have been provided. For example, more than one television set is utilized and the sets are each positioned for viewing by only a small segment of the people. However, this solution again adds to the cost, since many sets must be provided for single viewing by a large audience. Other solutions have provided the placement of a magnifying lens on the front of the television screen to enlarge the picture. However, the maximum size of enlargement is limited, and when attempts are made to increase the size, loss of clarity results whereby the image becomes out of focus and difficult to view.